'She's talking to that mirror again, farther?' says Misst Craddock. Father Cradock turns round slowly from the book he is eating and explains that it is just a face she is going through and they're all the same at that age.

Thursday, February 21, 2013

When I was pregnant, there were a battery of tests that my doc recommended, among them for a series of potential diseases that might damage the foetus. So, I obediently got them done. One of these tests came back positive: Toxoplasma Gondii. I consulted my trusty What to Expect and was horrified to discover that the thing sounded hugely dangerous. I was traumatised.

The doc recommended I re-do the test and the next one turned out negative ( though why disregard the first and accept the second? Would there be any way of finding out until it was too late?) and all manner of things were well after all.

So this Toxo thing seems like a special parasite, one that was (almost) mine. Naturally, all related reading are of interest. This piece suggests that this parasite - usually considered harmless in healthy adults and reasonably-sized children - actually can cause all kinds of changes in the brain.

She began tagging the parasite with fluorescent markers and tracking
its progress in the rats’ bodies. Given the surgically precise way the
microbe alters behavior, Webster anticipated that it would end up in
localized regions of the brain. But the results defied expectations. “We
were quite surprised to find the cysts—the parasite’s dormant form—all
over the brain in what otherwise appeared to be a happy, healthy rat,”
she says. Nonetheless, the cysts were most abundant in a part of the
brain that deals with pleasure (in human terms, we’re talking sex,
drugs, and rock and roll) and in another area that’s involved in fear
and anxiety (post-traumatic stress disorder affects this region of the
brain). Perhaps, she thought, T. gondii uses a scattershot approach, disseminating cysts far and wide, enabling a few of them to zero in on the right targets.

To gain more clarity on the matter, she sought the aid of the
parasitologist Glenn McConkey, whose team at the University of Leeds was
probing the protozoan’s genome for signs of what it might be doing. The
approach brought to light a striking talent of the parasite: it has two
genes that allow it to crank up production of the neurotransmitter
dopamine in the host brain. “We never cease to be amazed by the
sophistication of these parasites,” Webster says.